1. Field of the Invention
The present invention relates to a laminate film using a magnetic material and in particular to a magnetization-conduction interactive element, using the same, having magnetoresistance effect with high sensitivity.
2. Description of the Prior Art
Conventional magnetoresistive elements using a magnetic material include those constructed of a magnetic metal/nonmagnetic metal or laminate films, such as magnetic oxide/superconducting oxide/magnetic oxide, described in Japanese Patent Laid-Open No. 63249/1993.
A magnetoresistive element prepared by using the conventional laminate film exhibits a magnetoresistance effect as low as about 10% in a strong magnetic field of not less than 1000 Oe, or, even though the magnetoresistance effect could be attained in a magnetic filed of several Oe, exhibits a magnetoresistance effect as low as about 5%. Thus, the magnetoresistive element, when used as a magnetic sensor, creates only a small signal change, requiring a signal amplifier and signal calibration. Therefore, the construction becomes complicate, posing a problem that the cost involved in auxiliary devices is higher than that of the sensor per se. Further, since a switch utilizing magnetism is mechanically operated, there are problems associated with durability of a movable section, a large size of the movable section, limitation of the place where the switch may be installed. On the other hand, the perovskite type ferromagnetic material exhibits a large signal change. It, however, has a problem that somewhat large magnetic field is necessary. The present invention provides a simple magnetic sensor and a device material which can eliminate the need to provide any auxiliary device, such as an amplifier.